1. Field of the Invention
The present invention relates to a wind driven power generating system of single rotor type in which a horizontal and vertical shafts are combined. Specifically, the invention relates to a wind driven power generating system in which, under blowing of strong wind, the rotating blade is automatically and variably slanted backwards by means of a spring force without any pitch control while directing against the wind, thereby protecting the system and continuing the generation of electricity.
2. Background of the Related Art
In general, a wind driven power generating system generates electricity by using a blade driven by the wind power. That is, the kinetic energy due to rotation of the blade is converted into electrical energy, which is supplied to individual users. The conventional wind driven power generating system, according to the orientation of shafts, is categorized into a horizontal shaft system having a propeller, a vertical shaft system such as a Gyro-mill type and a Darius type, and a combination type system of vertical-horizontal shafts. As compared with nuclear, hydraulic, thermal power generation system, the wind driven power generating system is very economical in terms of the construction cost and area, and can avoid environmental contamination.
The conventional wind driven power generator is composed of a main body rotatably installed on the top of a tower, a blade mounted at the front end of the main body and rotated by the wind power, a gearbox such as an accelerator for accelerating the rotating power of the blade, and a power generator for converting the accelerated rotating power into electrical energy, and the like.
For the conventional wind driven power generator having the above-described construction, when the blade is rotated by the wind, the rotating power is accelerated through the gearbox. Then, the power generator produces electrical energy using the accelerated rotating power and the produced electrical energy may be either stored in an electrical energy storage unit or supplied directly to the users.
In the horizontal shaft type described above, the rotation torque transmitting path is rather short and thus provides an advantage of high efficiency of transmission. However, the main body with the power generator and the like equipped therein is heavy to the extent that it disturbs an easy yaw operation depending on the wind direction. Furthermore, after the body has been rotated by a certain number of times, the system operation must be intermitted in order to restore the twisted electric cable into the original state.
In addition, since the power generator is placed inside the main body, it cannot readily be cooled and maintained/repaired. Also, at emergency such as a strong wind, the system operation must be interrupted by means of the pitch control of blade in order to protect the system from overload of the power generator, and accordingly the generation of electricity is inevitably discontinued.
In the dual rotor type (the combination type of horizontal and vertical shafts), the wind power passing through the center portion of a main blade can be utilized by an auxiliary blade to produce a rotation torque, and thus can use the wind power efficiently. However, the opposite rotating directions of the main and auxiliary blades make it difficult to fabricate the blades, and a precision pitch control must be carried out with respect to each blade in order to uniformly combine the torque of the main and auxiliary blades, but practically a perfect pitch control cannot be easily achieved.
In the dual rotor type (the combination type of horizontal and vertical shafts), the wind power passing the center portion of a main blade can be utilized by an auxiliary blade to produce a rotation torque, and thus can use the wind power efficiently. However, the opposite rotating directions of the main and auxiliary blades make it difficult to fabricate the blades, and a precision pitch control must be carried out with respect to each blade in order to uniformly combine the torque of the main and auxiliary blades, but practically a perfect pitch control cannot be easily achieved.
Furthermore, similar to the horizontal type generating system, the manufacturing cost is rather high, and at emergency such as a strong wind the generation of electricity cannot be continued.